Spy vs Spy: The Island Caper is a competitive multiplayer game where the goal is to recover all the vital items and leave before the other player does the same. It’s a tropical-themed variant on the original.
The Island Caper plays almost identically to the original Spy vs Spy game, just with a graphically updated island theme. Instead of rooms full of fixtures that items might be hidden behind, the player must search beaches on islands for items buried in the sand. Specifically, they need to assemble a missile from its parts, presumably so it can be launched at the opponent spy’s home country. Finding the missile will allow the victorious spy to escape the island via a submarine (which inexplicably also includes an attractive woman). There are also traps which, like in the original, can be placed in spots where missile parts might be to fool opponents into killing themselves.
The game was released on many of the home computers and consoles active at the time. Curiously, it also received a Japan-only NES port named “Nangoku Shirei!! Spy vs Spy” published by Kemco.